WO2009034401A1

WO2009034401A1 - Designer color shades by computer simulation utility

Info

Publication number: WO2009034401A1
Application number: PCT/IB2007/002589
Authority: WO
Inventors: Milind Taskar
Original assignee: Datla, Ramesh
Priority date: 2007-09-10
Filing date: 2007-09-10
Publication date: 2009-03-19

Abstract

A color measurement instrument to develop the designer color shades with D/8, D/0, 45/), 0/45, D(hemisphere)/8, D(hemisphere)/0) or any other spectral geometry in the range of 350-1100 nm or with any wavelength combinations in visible region of user's choice, with the illumination source, integrating sphere (in case of D8), detector with an optical assembly between source and the sample &the sample and the detector for proper optical focusing using a variable sample aperture.

Description

Title:

Designer Color Shades by Computer Simulation Utility

Description of the invention:

The designer can choose the substrate (textile Dyeing/ Printing, Fiber Blend) onto which the specific color (designer color) of his choice would go. There are 6 available colorants, whose depth can be visualized as a function of its concentration. Based on the designer color, he can create it choosing 1-6 of the available colorants. The designer can play with the spinner wheels (which determine the concentration of the colors) to fine-tune the specific color of his choice. This color thus developed can be put on the object (car, chair, cloth, dress etc) of interest and a three dimensional view of the object with the specific color can be visualized. Further, this color can also be observed under different illuminants.

Background:

Designer colors are much sought after in every walk of life. Be it a car with designer color, be it Tee-Shirt, or Shirt, or Ceramic tiles for the home of the designer color. For that matter, a designer color gives the user a very happy feeling, and as such any material of designer color is costly. The process being patented describes the computer simulation of creation of designer color for textiles.

Prior Art:

People have worked on designer color in Paints, for homes and interiors, using computer simulations.

Over all design:

Spectrophotometer Specifications: Spectrophotometer. Bench top/ Portable.

Spectral range: 350-1100 nm. (Top of the line.)

Wavelength Interval: 1,5,10 user selectable.

Source: Pulsed Xenon, with D65 filters./Any other source.

Measurement Mode: % Reflectance and % Transmission.

Geometry: D/8.

Integrating Sphere: 6-Inch Diameter. Coated inside with BaSO4/ White Teflon.

Measurement principle: Double Beam/Single Beam.

Photometric Range: 0-200%.

Photometric Accuracy: 0.01% Reflectance. Or Transmission.

Measurement Apertures: 3 mm, 10 mm, and 24 mm (1 inch diameter)

Calibration: White Tile, Black trap.

SCI /SCE: Motorized.

UV filter: Motorized.

Spectra Geometry: This can be D/8, D/0, 45/0, 0/45, D (hemisphere)/8, D (hemisphere)/0

Invention patent applies to all the above geometries.

Process for Textiles:

DATABASE.

As the colorant database comprises of: o Reflectance values of the substrate in the range 350-760 nm. o A number of substrates can be stored for the Reflectance values 350-760 nm. o The Reflectance values of colorants (dyes) made as finite concentration levels, as under are stored in the range 350-1100 nm. o 0.01%, 0.025%, 0.05%, 0.1%, 0.25%, 0.5%, 1.0, 1.5%, 1.75%, 2.0%, 2.5%, 3.0,

4.0%, 5.0%. o This is an example the concentration levels are decided by the user by the working range of the colorants (Dyes). There are finite levels for each colorant, o For one colorant the concentration levels may be 10, for the other it might be 15, for the third it may be 20. o The range of concentration may also be different, o The Substrate/s and concentration levels of all colorants are Color spectrophotometric measurements in the range 350-760 nm. o Different models of Color Spectrophotometers may have different spectral ranges and intervals like 350-760 nm, 360-760 nm and 400-700nm

From the Reflectance Database, by Kubelka Munk equation the K/S are generated for substrate and each concentration level of Colorant.

Thus we have data. Substrate: λ ( K/S) Substrate

400 value

405 value

410 value

415 value

700 value

Colorants (Dyes): λ K/S(0.01) K/S( 0.025) K/S(0.05) K (0.1) K/S(5%)

400 value value value value value

405 value value value value value

410 value value value value value

415 value value value value value

700 value value value value value for all colorants(Dyes.)

Note: 1. From this database in the range 400-700 nm the above calculations for generating Color/Color Synthesis are done for color match. This can also be 360-760 nm or 350- 760 nm.

2. The interpolation used for (KIS) versus concentration as required for equation (4) could be linear, or Lagrange or polynomial, or any suitable interpolation equation.

Reflectance of the mix (for the designer color) is synthesized by the following Color Synthesize formula, in the range 360-700 nm. This is done for all the mixes of designer colors, using concentration additive color mix with K/S.

From the (K/S)mκ we can calculate the predicted designer color Reflectance in the range 400-

700 nm ranges by the quadratic equation.

Thus we have Reflectance of mix in the range 400-700 nm.

The Reflectance of the color to be added to the designer color is converted in to tristimulus values X Y Z.

K is called the normalization constant for the condition for %Reflectance =100% for a perfect

Reflector, Y=100.

We employ the D65 CIE tables from the technical Bulletin of CIE for Energy Distribution of D65 llluminant. The CIE D65 table are 5 nm based. We do a Lagrange interpolation and calculate the data at 1 nm, from 5 nm, and store in the tables, for 1 nm interval.

The xbar, ybar, z,bar table for 10 degree observer 1964 are taken from Wyszecki Stiles book at

1 nm interval.

We then use sRGB color space for X Y Z to R G B conversion. This is given below:

We first decimalize the X Y Z values. So, we get the R G B values, as unitary scale for D65 llluminant, and 10 degree Observer.

We convert the R G B thus obtained to 0 to 255 scales.

R⁼ R unitary X 255 G= G unitary X 255 B= B unitary X 255

The above R G B we employ for creation of three-dimensional designer color, in addition of two dimensional shade cards.

Note: the X Y Z to R G B can be done as per various RGB Color Spaces like:

Adobe

Apple

Best RGB

Beta RGB

Bruce RGB

NTSC

CIE

Color Match.

DonRGB4

ECI

Ekta Space PC5

PAL/SECAM

Prophoto. SMPTE-C.

Widegamut.

RGB Space Gamma Ilium

Adobe RGB (1998) 2.2 D65

Apple RGB 1.8 D65

Best RGB 2.2 D50

Beta RGB 2.2 D50

Bruce RGB 2.2 D65

CIE RGB 2.2 E

Color Match RGB Space 1.8 D50

Don RGB 42.2 D50

ECI RGB 1.8 D50

Ekta Space PS52.2 D50

NTSC RGB 2.2 C

PAL/SECAM RGB 2.2 D65

Prophoto RGB 1.8 D50

SMPTE-C RGB 2.2 D65 sRGB ^«2.2 D65

Wide Gamut RGB 2.2 D50

This is done employing Bradford's Chromatic Adaptation Transform.

Thus by making the measurement in D65/10 degree, we can do the Chromatic Adaptation transform to any other llluminant /Source.

This enables us to depict the three-dimensional designer color in any user switched on illuminant.

Rendering algorithm on three dimensional objects of the user's choice: User is given a choice for the three-dimensional objects of his choice on which the color is to be rendered in textile industry.

Note: The X Y Z to R G B conversion can be done under the following RGB Color Spaces.

A library of such object is made as BMP, JPG files. The above objects in the library are converted in to gray images and the library is kept as library of gray images, of the type three- dimensional type. So we have a large library of three dimensional BMP, or JPG images that are gray.

Rendering algorithm:

Once the object is selected say Tee shirt. The programme scans the gray image for the individual pixels of the gray image

The gray image consists of pixels where R=G³B, or R and G and B are equal at various levels from O to 255.

For example, the scan may find 80% population of pixels where R=123 G=123 and B=123 10% population where R= 75 G=75 and B= 75, and so on. So, we have to find out which group of pixels with the same R G B is in majority.

We assign the R G B of the color to be rendered to this group of pixels, which are in the majority in the three dimensional object.

Now, the gray group with R G B higher will get R+(difference in R), G -^Difference in G), and B +(Difference in B) to give a lighter color to the group.

Now, the gray group with R G B lower will get R-(difference in R), G -(Difference in G), and B - (Difference in B) to give a darker color to the group.

Any group of pixels R and G and B > 255 R and G and B =255.

Also, any group of pixels R and G and B < 0 R and G and B = 0

Thus the whole three dimensional object will be at various pixels shades darker and lighter of the same color to produce the dimensional color render of the R G B to be rendered.

Any suitable render algorithm, other than the above may be used for the purpose of creating designer colors.

% Reflectance of each Shade in case required for matching etc.

The three dimensional designer color on the choice of user's own objects can be thus made.

Each color shade is shown as a three-dimensional color rendered on the object of user's choice of the size as desired by the user.

Utility value:

The design of the utility:

The purpose of the utility process to be patented is allowing the user to create Designer color, which possibly, did or did not exist in any shade card. The purpose of the utility is create something like kaleidoscope of T-Shirts or a whole gamut of Colors in Shirts etc., without the need to do the actual dyeing/printing. The mixing of Colorants (Dyes) is a computer simulation, where the user sits in front of a Super VGA, and by simple mouse click of Spinner wheel adds/removes different colorants on to a substrate. The process is, The user is allowed to select 1. A Substrate 2. From the available pool of colorants, 1 to 6 colorants to mix and create a new color from.

Now, the user enters the world of creation of a Designer Color.

If the user has a penchant or predilection for a violet color, or he wants to make a violet shade of his creation as designer color for his T-Shirt, he will select.

1. A violet Colorant.

2. A Red Colorant.

3. A Blue colorant.

4. A Black also to give depth.

By playing with the spinner wheel, where by each add/removal generates designer color, which he monitors, and renders on the object of his choice like TEE-Shirt.

Thus, he can create a virtual Kaleidoscope of T-Shirts of various color shades.

One, which he likes, he evaluates in different lighting conditions like CWF, Bulb, D65 etc., for color.

This can be a stand-alone system without the spectrophotometer also at a departmental store. The data of colorant must be the same as the data being used in the production unit.

This computer simulation can create a new wave in the fashion industry.

Brief Description of Drawings

Fig1 gives the schematic of the optical measurement instrument used for the above application.

Description of Preferred Embodiment

1. Lamp/Diode Array Power Supply: It is used to switch on and off the xenon flash lamp and diode array.

2. Xenon Flash Lamp: They are convenient source for UV and visible light. These lamps are compact and generate a minimal amount of heat and are available in sizes ranging from 5 to 60 watts. The amount of output light, pulse width and repetition rate can be easily controlled.

3. Integrating Sphere:

3.1: Entrance port of the light source into the integrating sphere and 3.3: Baffles to avoid direct light from the xenon source to fall on the sample, so that the sample receives purely diffused light. 3.4: Sample port

3.5: SCI/SCE: Specular component included or excluded. It is a lid hinged out and in to be used as a specular trap. 3.6: Exit port of the sphere

4. Sample Position: The liquid or the solid sample (from standard or batch) is placed here.

5. Collecting Optics: It receives radiation reflected from the sample 8° normal to the sample surface, with the angular collection tolerances specified by CIE and ASTM₁ DIN and focuses on the fiber couple.

6. Fiber coupling: It receives the focused light and transferred to the spectrum analyzer.

7. Spectrum Analyzer:

7.1 : Entrance slit of the spectrum analyzer and exit port of the fiber optic probe

7.2: Mirrori: Collimating concave mirror that collects the signal from the entrance slit to the grating.

7.3: Grating: Plane reflection grating of 300/600 lines/mm used for dispersion of light into respective colors.

7.4: Mirror2: De collimating concave mirror grating to diode array.

7.5: Diode array detectors: It consists of individual photodiodes with number of pixels defined, so as to have the specific band of wavelengths. Band pass - 1 nm. The photodiodes convert the light signal to electrical signal. Strength of the electrical signal is proportional to the light intensity.

8. I/O Card: It has a necessary interfacing circuitry for CMOS linear image sensor and communicates with PC via USB

9. PC: Used for collecting and analyzing the data through the software developed for the application.

Claims

Claims;

1. A color measurement instrument to develop the designer color shades with D/8, D/0, 45/0, 0/45, D(hemisphere)/8, D(hemisphere)/O or any other spectral geometry in the range of 350-1100 nm or with any wavelength combinations in visible region of user's choice, with the illumination source, integrating sphere (in case of D8), detector with an optical assembly between source and the sample & the sample and the detector for proper optical focusing using a variable sample aperture.

2. An instrument according to claim 1, wherein has a wavelength interval of <1nm, 1 nm, 5 nm, 10 nm, 20 nm or user selectable and measurement principle is single/double beam and is also preferred to as color spectrophotometer.

3. An instrument according to claim 1 , wherein produces a designer color based on a computer simulation, where a user on a super VGA screen, with a simple mouse click of a spinner wheel, mixes different colorants, by adding or removing on to a substrate of his choice.

4. An instrument according to claim 1, wherein can allow the user to select a substrate and available pool of colorants (say 1 to n) (dye stuff, soap pigments etc) and create a new designer color or a number of designer colors of user's choice.

5. An instrument according to claim 4, wherein pool of colorants are not limited to dye stuff, soap pigments or 1 to n.

6. An instrument according to claim 1 , wherein can allow the user to design a single solid color or a number of motifs with different designer colors on any size of any substrate of his choice.

7. An instrument according to claim 1, wherein allows the user for a two or three dimensional color blend of the designer color developed by him.

8. An instrument according to claim 1, wherein allows the user to view his designer color under different lighting conditions like but not limited to CWF, Bulb, D65 for evaluating the color.

9. An instrument according to claim 1 , wherein can use any suitable algorithm of the three-dimensional render of the designer color.

10. An instrument according to claim 1 , wherein the development of the designer color can be a stand-alone system with out the instrument above claimed.